One form of known grain probe is a hollow tube with a closed nose end and a valve in the tube spaced from the nose. A probe of this sort is inserted into the grain to the depth desired, the valve is opened to allow a sample of grain to enter the tube and then the tube is withdrawn along with the sample. The sample may be poured out of the upper end of the tube for subsequent testing. Known probes of this sort suffer from a number of disadvantages, including difficult insertion and/or withdrawal of the probe, unreliable valve operation and unwieldy dimensions.
The present invention proposes certain improvements in grain probes of this sort.